Hydrazo esters



Patented Dec. 5, 1950 HYDRAZO ESTERS Paul J. Flory, Kent, and Norman Rabjohn, Akron, Ohio, as'signors to Wingfoot Corporation, Akron, Ohio, a corporation of Delaware 7 No Drawing. Application January 16, 1946,

Serial No. 641,651

- 8 Claims. 1

This invention relates to a new group of chemical compounds having valuable properties as hereinafter described. More specifically, the invention relates to new esters having a plurality of hydrazo radicals (NH-NH) and to methods for their preparation.

The purpose of this invention is to provide a new class of chemical compounds which are useful as intermediates in the preparation of valuable polyazo compounds. A further purpose of this invention is to provide methods of synthesizing polyhydrazo derivatives.

The new compounds have the general struc tural formula .l L p O O R[O( NHNHg-OR],

in which R may be a monovalent hydrocarbon radical, such as alkaryl, alkyl, aralkylyaryl, a monovalent oXa-hydrocarbon radical such as alkoxyalkyl, aryloxyalkyl or alkoxyaryl radicals, a thiahydrocarbon radical such as arylene, alkyl arylene, a multivalent oxa-hydrocarbon radical, such as the polyalkylene glycol and ' radicals, the divalent arylene ether radicals, and

the mixed alkylene arylene ether radicals, the multivalent thiahydrocarbon radicals, such as (alkylene-Salkylene-), and the corresponding alkyl-, halo-, and nitro-substituted radicals, and in-which m is a small whole number greater than one but preferably from two to five inclusively.

The monovalent radical designated as R, in the above structural formula may be an alkyl radical, such as methyl, ethyl, hexyl, cetyl and melissyl radicals, an aryl radical such as phenyl and naphthyl radicals, an aralkyl radical, such as benzyl, phenylethyl and naphthylmethyl radicals, a cycloalkyl radical, such as cyclohexyl and cyclopentyl, an alkoxyalkyl radical, such as 2- methoxyethyl, 2-ethoxyethyl, and the Z-isopropoxy-n-propyl, a thia-alkyl radical, such as (CH3SCH2) an alkoxyaryl radical, such as methoxyphenyl and ethoxynaphthyl radicals, and the alkyl-, halo-, and nitro-substituted radicals, such as tolyl, xylyl, 2-chloroethyl, S-brornopropyl, fluoromethyl, para-chlorophenyl, metaethylphenyl, 2-nitroethoxymethy1, and 2,4-dinitrobenzyl radicals.

The multivalent radical designated as R in the above structural formula may be any alkylene radical, such as ethylene, hexamethylene, decamethylene, and 1,2-propylene radicals, the oxaalkylene radicals, such as the radical derived from diethylene glycol, the radical derived from triethylene glycol and the corresponding thio ether alkylene radicals, such as (C2H4S-C2H4SC2H4) an arylene radical, such as the para-phenylene radical and the various naphthylene radicals, a divalent radical having both aryl and aliphatic characteristics,

1 such as 2,2 bis (diphenylene 1,4) propane the halo-, alkyl-, and nitro-substituted derivatives of any of the above radicals, a radical having a valence greater than two, such as glyceryl, pentaerythryl (the quadrivalent radical'derived from pentaerythritol) and similar aliphatic or aromatic hydrocarbons, thiahydrocarbons on,

oxahydrocarbons, and the corresponding alkyl-, halo-, or nitro-substituted radicals.

The new hydrazo esters are prepared by reacting a polychloro carbonate of a polyhydroxy compound having the desired multivalent radical of the types above described, with an ester of hydrazine monocarboxylic acid wherein the carboxylate radical is linked to the desired monovalent radical of the types described above, thereby producing compositions containing a plurality of hydrazo radicals (-NHNH-).

The polychlorocarbonates are prepared by reacting any polyhydroxy compound, involving the desired polyvalent radical as above described; with phosgene until all of the hydroxy radicals,

or at least a plurality of the hydroxy radicals, are substituted with chlorocarbonate radicals a O (-0 -Ol) 3 The polychlorocarbonates are preferably prepared by adding the polyhydroxy compound gradually to an excess of liquid phosgene while maintaining a temperature below 10 C. for the purpose ofi'removi'ng the heat ofreactiomaswell as to retain the phosgene in liquid state. It isdesirable to surmount the reaction flask with a reflux condenser cooled below the boiling point of phosgene for the purpose of condensing the. phosgene gas and returning the same to the reaction vessel. may be purified by distillation, although many can be satisfactorily purified by Washing with Water, or by warming to removeexcess phosgene.

and hydrogen chloride.

The polyhydroxy compounds having aryleringsubstituted hydroxy radicals may also be used in the preparation of polychlorocarbonates but the presence of a basic reagent is then also required. Suitable basic reagents are the tertiary amines, such as pyridine and triethylamine and the alkali oralkali earth metal hydroxides, carbonates, or oxides, such as sodium hydroxide and potassium carbonate.

The esters of hydrazo monocarboxylic acids may be prepared by reacting hydrazine hydrate with the carbonicacid ester havin the monovalent organic radical desired in the final composition. Thus, diphenyl carbonate, diethyl carbonate, dibenzyl carbonate and. any other carbonate ester may be reacted with an equal molecular proportion of hydrazine hydrate. The reaction takes place immediately, although generallyit is desirable to stir the reaction mass and heat it slightly to, complete the reaction.

The resulting ester is usually a solid which can be separated from the reaction mass by adding water and then recrystallized from alcohol solutions.

, The condensation of the polychlorocarbonates with the esters of hydrazine monocarboxylic acid are conducted in a solution of a suitable solvent, such as dioxane, and in the presence of a basic reagent, such as dimethyl'anili'ne, pyridine or other tertiary amine, or the oxides, carbonates, or hydroxides of an alkali or an alkali earth metal.

The resulting bis hydrazo. ester may then be separated b adding water to the reaction mass and purified by recrystallization, for example from ethyl acetate or a mixture of ethyl acetate and petroleum ether.

The following are examples of compounds which may be prepared in. accordance with this invention:

V Decamethylene-bis(-ethyl hydrazodicarboxylate) if n u u CzH OCNH'-N'HCO(CH2)10-O-C-NH-NH-C-O-C2H Diethylene-bis(-phenyl hydrazodicarboxylate) Some of the dichlorocarbonates Glyceryl-tris (benzyl hydrazodicarboxylate) Para-phenylene-bis cyclohexylhydrazo dicarboxylate) Thiodiethylene his(gamma-chloropropylhydrazo Bam-xylylenerbismetaemethoxyethylehydmzodicarboxylnte) 2,2-p,p' di(hy droxyphenyl))propane bisLp-nitro phenyl hydrazo; dicarboxylate ester The new bis hydrazo compounds described" above are useful as intermediates in, the preparation of bis, azo. derivatives" which are capable ofcuringar-ubber without-heat. In copendin ap plicatiorr Serial No., 641,650, filed January 16,.

1946.,by'Paul-J; Flory andNorman-Rabjohn therearedescribed; and claimed methods ofv preparing:

the; his azo; derivatives. In copending applica tion SerialNm 6.41 .552. filed January 16, 1946, by-

Paul J El'ory and Norman Rab'john, now U. S;

Patent 2369.819; thereare; described and claimedmethods of vulcanizing rubber by means of the:

bisazo esters.

Furtherdetails of the preparation of the his hydrazo compounds are set forth in the follow ing specific examples.

Example 1' trat'e distilled under reduced pressure. A substantial proportion of dibenzyl carbonate was obtained (B. P. 175-180 C. at 4 mm.). A mixture of 35.5 grams of dibenzyl carbonate and 10.5 grams of 85 percent hydrazine hydrate was stirred and warmed until a homogeneous solution resulted. It was allowed to stand overnight at room temperature and then poured into 100 cc. of water to form two liquid phases. The nonaqueous phase was separated and heated at 100 C. and 3 mm. pressure for four hours. The residue solidified upon cooling and the hydrazine monocarboxylic acid benzyl'ester was separated (M. P. 63-65 0.). A portion of the ester (10.4 grams) was dissolved in 75 cc. of dioxane in a fiask and solutions of 4.76 grams of potassium hydroxide in 50 cc. of water and grams of pphenylene dichlorocarbonate in 150 cc. of dioxane were added gradually thereto. The reaction mixture was stirred. without cooling and the heat Of reaction caused an appreciable increase in temperature. After the reaction mass had cooled to room temperature it was poured into 600 cc. of water. A solid compound was obtained which was purified by crys allization from alcohol solu-, tion (M. P. 186-187 C.) and Was identified as para phenylene bis (benzyl hydrazodicarboxylate) having the structure: f

Using an apparatus similar to that described in the preceding example, a solution of 20.8 grams .of hydrazine monocarboxylic acid ethyl ester in complete the reaction mass was warmed for 45 minutes. After cooling to room temperature the solid triethylamine hydrochloride was removed by filtration; the dioxane was evaporated under reduced pressure and the diethylene glycol bis- (ethyl hydrazo-dicarboxylate) so obtained was recrystallized from ethyl acetate (M. P. 130-132 C.). The compound had the following structure:

o i ll ll CzH4-O CNHNH-- -OC2Hs Example 3 Using a procedure analogous to those described in the preceding examples, a solution of 12 grams of hydrazine monocarboxylic acid methyl ester in 200 cc. of dioxane was placed in a flask. S0lu-.

6. having a M. P. of 112-114 C. It was identified gas the bis(methyl hydrazo-dicarboxylate) ester pf decamethylene glycol having the following structure:

To a solution of 50 grams (0.5 mole) of phosgene in 500 cc. of dry toluene were added dropwisesolutions of 57 grams (0.25 mole) of 2.2-- bis p,pdi(hydroxyphenyl) propane in 250 cc. of dioxane and 60.5 grams (0.5 mole) of dimethyl- .faniline dissolved in 60 cc. of dioxane. The reaction mixture became warm and was subsequently heated on a steam bath for three hours. iIt was allowed to stand several hours and a precipitate of dimethyl aniline hydrochloride formed. This precipitate was removed by filtration and the filtrate concentrated under reduced pressure. There was obtained 6'7 grams of an oil which gradually solidified; M. P. 88-90 C. It was the bis-chloroformate ester of 2,2-(p,p'- di(hydroxy-phenyl) propane.

To a solution of 20.8.grams (0.2 mole) of hydrazine monocarboxylic acid ethyl ester in cc. of dioxane were added 35.3 grams (0.1 mole) of 2,2-(p,p'-di(hydroxyphenyl)) propane bischloroformate dissolved in cc. of dioxane and 20.2 grams (.2 mole) of triethylamine, dissolved in 100 cc, of dioxane. After all had been added, the m xture was stirred for an hour, filtered to remove the precipitate 'of amine hydrochloride, and the filtrate concentrated. The residue was dissolved in a mixture of ethyl acetate and hexane and allowed to stand. A white solid gradually precipitated. There resulted 28.3 grams of material which melted at 169 to 171 C.

The compound was identified as 2,2- (p,p' di (hvdroxyphenyl) )propane bis (ethyl hydrazo dicarboxylate) ester having the structure:

Other polyhydrazo compounds may be prepared by reacting polychlorocarbonate esters with hydrazine. Such compounds prepared from dichlorocarbonates are linear polymers and have the structure:

0 Laamaaaaa].

Other cross-linked polymers can be prepared from polychlorocarbonates having three or more chlorocarbonate groups. SLlJCh polymers may be defined structurally as follows:

i l i i R- OC-NH-NHCO-,=-

where arepresents the valence of R and is greater than one, and represents the number of R molecules in a polymer chain,

Although the invention has been described with respect to specific modifications, it is not intended that the invention shall be limited by the details thereof except to the extent incorporated in the following claims.

I:We:cia1m;.

As: a; new composition the compound. having; structural. fonnula.

atoms being connected to carbon atoms in R;-

and and" aris a small whole number between 2' and 5- inclusive:

' 2 As a new chemical compound the compound having the structural formula R is a monovazlent hydrocarbon radical and r is a small whole number between 2' and 5 incl usi've.

3. a new chemical? compound diethylene glycci. bi'si ethyl hydrazc dinarboxylate) 4. As a new chemical compound decamethylene bisK-methyl hydrazo dicarboxylate).

51 As a new chemical compound p-phenylene' bis(benzyl" hydrazo" dicarboxylatel-u 61A method oi. preparing a: compound havihg: the: structural formula.

1 t i- 1 R'[O-CNH-NH--OR Q wherein; R. is a;- polyvalent radical of the group consisting. of hydrocarbon}. oxahydrocarbon and.

as thiahydrocarbonradicals and. the corresponding; nitro and halogemsubstituted radicals, R is;v a: monovalent nadicah of: the group consisting oi hydrocarbon, oxahydroca-rbon and: thiahydmycarbonradicals and the corresponding. nitro.- a-nda halogenesubstituted radicals.-,. the oxygen, atoms being connected to carbonatoms in: Rt 211MB, and x isa small whole number between 2 and 5 inclusive, which; comprisesv reacting. the

with a: molecular equiyalents of the compound;

compound HiN"NH-%OR" in the presence of a basic reagent, R, R" and a? being as above defined.

7. As a new chemical compound, an alkylenc bis (alkyl hydrazo dicarboxylate).

8. As a new chemical compound, a poI'yalJ- kylene glycol bis (alkyl hydrazo dicarboxylate'l.

PAUL J. FLORY. NORMAN RABJOHN.

REFERENCES CITED The following references are of record; in the; file of this patent:

UNITED- STATES PATENTS Number Name Bate 1,817,992 Leopold et a1. Aug. 111, 1932 2,378,571 Moldenhauer et al. June 19, 1945- 2,401,549 Chenicek June 4', 1946 OTHER. REFERENCES Diels et all: Berichte,.. vol. 44 (1911), p. 3025. 

1. AS A NEW COMPOSITION THE COMPOUND HAVING THE STRUCTURAL FORMULA 